Detachable securement of a cable to a cable drum

ABSTRACT

A cable drum has a groove for guiding a cable which has an enlarged end. The groove has an end zone which terminates in an abutment surface extending inside the cable drum and has a depth which steadily increases in the area of the end zone in the direction of the abutment surface. The cable drum has a through opening which substantially extends transversely to a drum wall for passage of the enlarged cable end to rest against the abutment surface which is oriented substantially in a mid-plane which extends through the longitudinal axis of the cable drum. The drum wall of the cable drum is formed interiorly along the groove adjacent to the abutment surface with a depression for at least partially receiving the enlarged cable end, wherein the depression has a bottom against which the enlarged cable end rests, when the cable end assumes a fixation position.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the priority of German Patent Application Serial No. 101 07 390.9, filed Feb. 7, 2001, the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a detachable securement of a cable to a cable drum.

[0003] U.S. Pat. No. 2,329,943 discloses a cable end securement to a cable drum having a helical groove, which guides the cable. The cable end is enlarged to form a cylindrical block which, when the cable end assumes the fixed position, bears upon a contact surface which is formed on an abutment inside the cable drum. For assembly, the cable end is fitted through an opening extending transversely to the drum wall. The opening is closed by a threadably attachable closing element which has formed therein a cable groove for guiding the cable end. The cable groove of the closing element has a depth which steadily increases toward the contact surface, with the cable groove terminating in the area of the contact surface.

[0004] This conventional cable end securement suffers shortcomings as far as overall dimension is concerned because the cable drum is fairly wide and thus requires much space in radial direction. Moreover, the securement of the cable end is difficult to install.

[0005] U.S. Pat. No. 1,533,556 discloses a cable end securement in which the contact surface lies substantially in a mid-plane which extends through the longitudinal axis of the cable drum. In order to enable fabrication of the mid-plane in a casting process, an expendable core is used, whereby the mid-section has a slot which is difficult to make. Securement of the cable end is relatively complicated as the cable end has to be pushed deep into the through opening in order to inwardly pivot the cable in the slot under visual guidance.

[0006] It would therefore be desirable and advantageous to provide an improved detachable securement of a cable to a cable drum to obviate prior art shortcomings and to so configure a cable drum as to be of slender size and easy to install.

SUMMARY OF THE INVENTION

[0007] According to one aspect of the present invention, in a detachable securement of a cable to a cable drum, the cable drum has a surface formed with a groove for guiding the cable, with the cable having an enlarged end for movement into a fixation position with the cable drum through inward pivoting, wherein the groove has an end zone which terminates in an abutment surface extending inside the cable drum transversely to the groove, with the groove having a depth which steadily increases in the area of the end zone in the direction of the abutment surface, wherein the cable drum has a through opening which substantially extends transversely to a drum wall for passage of the enlarged cable end to rest against the abutment surface, wherein the abutment surface is oriented substantially in a mid-plane which extends through the longitudinal axis of the cable drum, wherein the drum wall of the cable drum is formed interiorly along the groove adjacent to the abutment surface with a depression for at least partially receiving the enlarged cable end, and wherein the depression has a bottom against which the enlarged cable end rests, when the cable end assumes the fixation position.

[0008] According to another feature of the present invention, the through opening is located in the direction of the cable groove behind the abutment surface and intersects the depression.

[0009] According to another feature of the present invention, the through opening, the depression and the abutment surface are so disposed along the groove and an imaginary prolongation of the cable groove that the cable end can be pivoted inwardly into the fixation position about an imaginary axis which extends transversely to the groove and to the cable. In this way, the installation becomes very comfortable and easy.

[0010] According to another feature of the present invention, the cable drum may be formed in one piece with the groove and the depression as well as the through opening, thereby simplifying the manufacturing process. The manufacturing process can be further simplified by making the cable drum through a metal casting process. Hereby, it may be suitable, to provide the abutment surface on a continuous radial enlargement of the drum wall inside the cable drum. Suitably, the radial enlargement extends over an angular range of at most 45 degrees.

[0011] According to another feature of the present invention, the enlarged cable end may be formed as mounting clamp. Securement of the mounting clamp in the depression may be improved when the clamp is configured in the form of a cylinder and has an outer surface resting linearly against the bottom of the depression. The tendency of the clamp to separate from the depression, when the cable is slacked, can be avoided by providing a distance between the abutment surface and the through opening so as to provide a form-fitting engagement when the outer surface linearly rests against the bottom of the depression.

BRIEF DESCRIPTION OF THE DRAWING

[0012] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:

[0013]FIG. 1 is a front view of a cable drum according to the present invention, showing in detail the cable groove in the area of the detachable securement;

[0014]FIG. 2 is a partially sectional side view of the cable drum with the cable end being inserted;

[0015]FIG. 3 a partially sectional side view of the cable drum with cable end being pivoted inwardly into a fixation position;

[0016]FIG. 4 is a perspective view of the cable drum of FIG. 1, showing in detail the cable groove; and

[0017]FIG. 5 is a perspective view of the cable drum, showing in detail the through opening for the cable end, as viewed from inside the cable drum.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0018] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.

[0019] Turning now to the drawing, and in particular to FIG. 1, there is shown a front view of a cable drum 1 according to the present invention. The cable drum 1 is defined by a longitudinal axis 7 and has a surface in the form of a helical cable groove 2 for guiding a cable 3 having one end to be secured to the cable drum (FIGS. 2 and 3). The groove 2 terminates in an end zone 102 which is wider than the remainder of the groove 2 so as to allow placement of two cable windings in immediate side-by-side disposition over an angular range without separating ridge. The cable drum 1 may be made through a metal casting process in single-piece configuration. As shown in particular in FIGS. 2 and 3, the groove 2 has a depth which steadily increases in the end zone 102 towards a cable entry area, generally designated by reference numeral 4 and located immediately adjacent an abutment surface 5. The abutment surface 5 may either coincide with a mid-plane 6 of the cable drum 1, which mid-plane 6 intersects the longitudinal axis 7 of the cable drum 1, or, as shown in FIG. 2, extend at a slight distance in parallel relationship to the mid-plane 6. Thus, the abutment surface 5 extends substantially transversely to the groove 2 inside the cable drum 1.

[0020] Arranged behind the groove 2 at a slight distance to the abutment surface 5, the cable entry area 4 has a through opening 8 which extends transversely through the drum wall of the cable drum 1, as shown in FIGS. 2 to 4. The through opening 8 intersects hereby a depression 9 which is located along the groove 2 at a distance behind the abutment surface 5 and formed into the drum wall. The depression 9 has a bottom 10 which extends transversely to the mid-plane 6 in the exemplified embodiment. As a consequence of the distance between the abutment surface 5 and the through opening 8, a corner 11 is formed by the depression 9 is on the right hand lower side in FIG. 2.

[0021] As shown in particular in FIGS. 2, 3 and 5, the abutment surface 5 is formed on a continuous radial enlargement 12 of the drum wall inside the cable drum 1. The radial enlargement 12 extends in the exemplified embodiment over an angular range of equal or less than 45 degrees.

[0022] As shown in FIGS. 2 and 3, the end of the cable 3 being secured to the cable drum 1 has an enlarged portion 13 to form a mounting clamp 14.

[0023]FIGS. 2 and 3 show the securement of the cable 3 to the cable drum 1. The cable end formed with the mounting clamp 14 is inserted from outside through the through opening 8, whereby the cable end extends substantially parallel to the mid-plane 6. Then, the cable 3 is moved inwardly into the depression 9 to assume the fixation position, i.e. the cable 3 is pivoted about an imaginary axis extending transversely to the cable 3 by an angle of 90 degrees. In the fixation position, the mounting clamp 14 is almost completely received in the depression 9 and, as shown in FIG. 3, rests substantially linearly against an outer surface area of the bottom 10. A form-fitting engagement is realized in the corner 11 for restraining the mounting clamp 14 in the depression.

[0024] While the invention has been illustrated and described as embodied in a detachable securement of a cable to a cable drum, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. 

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents:
 1. In a detachable securement of a cable to a cable drum, the cable drum is defined by a longitudinal axis and has a surface formed with a groove for guiding the cable, with the cable having an enlarged end for movement into a fixation position with the cable drum through inward rotation, wherein the groove has an end zone which terminates in a abutment surface extending inside the cable drum transversely to the groove, with the groove having a depth which steadily increases in the area of the end zone in the direction of the abutment surface, wherein the cable drum has a through opening which substantially extends transversely to a drum wall for passage of the enlarged cable end to rest against the abutment surface, wherein the abutment surface is oriented substantially in a mid-plane which extends through the longitudinal axis of the cable drum, wherein the drum wall of the cable drum is formed interiorly along the groove adjacent to the abutment surface with a depression for at least partially receiving the enlarged cable end, wherein the depression has a bottom against which the enlarged cable end rests, when the cable end assumes the fixation position.
 2. The cable drum of claim 1, wherein the through opening is located in the direction of the cable groove behind the abutment surface and intersects the depression.
 3. The cable drum of claim 1, wherein the through opening, the depression and the abutment surface are so disposed along the groove that the cable end is pivotable inwardly into the fixation position about an imaginary axis extending transversely to the groove and to the cable.
 4. The cable drum of claim 1, wherein the drum wall has formed interiorly therein a continuous radial enlargement, with the abutment surface being configured at the enlargement.
 5. The cable drum of claim 4, wherein the enlargement extends over an angular range of equal or smaller than 45 degrees
 6. The cable drum of claim 1 formed in one piece with the groove and the depression as well as the through opening.
 7. The cable drum of claim 1 manufactured by a metal casting process.
 8. The cable drum of claim 1, wherein the enlarged cable end is formed as mounting clamp.
 9. The cable drum of claim 1, wherein the mounting clamp has a cylindrical configuration and includes an outer surface which is intended to rest linearly against the bottom of the depression.
 10. The cable drum of claim 9, wherein the cylindrical mounting clamp is held in position against a confronting end face of the drum wall in the fixation position.
 11. The cable drum of claim 1, wherein the abutment surface is spaced from the through opening by a distance.
 12. A cable drum, comprising a drum body having an outer surface formed with a groove intended for guiding a cable, wherein the groove has an end zone which terminates in a through opening for entry of a cable end and has a depth which steadily increases in the direction of the through opening, wherein the drum body is formed interiorly with a depression which is intersected by the through opening and extends in the direction of the groove, wherein the cable end rests against a bottom of the depression, when the cable is pivoted inwards for securing the cable end.
 13. The cable drum of claim 12, wherein the drum body has formed interiorly therein a continuous radial enlargement, to thereby form an abutment surface for support of the cable end.
 14. The cable drum of claim 13, wherein the through opening is located in the direction of the groove behind the abutment surface.
 15. The cable drum of claim 13, wherein the enlargement extends over an angular range of equal or smaller than 45 degrees
 16. The cable drum of claim 12, wherein the abutment surface is spaced from the through opening by a distance. 